MOSFETs and other types of transistors are found in many modern semiconductor products where switching and/or amplification functions are needed. Speed requirements of MOS transistors continue to increase in order to facilitate higher speed switching frequencies, more phases, and faster transient response for improved product performance. In recent years, the size of MOSFET transistors and other related MOSFET components have only slightly decreased, while available printed circuit board (PCB) space has decreased at a faster pace to facilitate smaller and more portable electronic products. At the same time, many new applications of such devices have created a need to operate high current high speed MOSFET transistors and other such MOSFET devices at increased operating efficiency and reduced circuit losses. Accordingly, efforts continue to be made to design MOSFET products, which occupy less physical space, consume less power, and operate at higher switching speeds with a fast transient response.
Power MOSFETs are useful for these high current high speed switching applications such as power conversion products including DC to DC converters, DC to AC inverters, AC to DC switching power supplies, and switching power regulators. For example, power MOSFETs may be designed into high performance DC/DC converter applications such as notebook, server and VRM modules. Although several quasi-standard device footprints have been established for MOSFET transistors, the pool of standardized parts and such alternate or second-sources is limited, particularly in regard to package layouts that are available for higher current devices. Further, the design of such power MOSFET products has traditionally been done from the schematic for the desired end product. This approach, however, commonly yields an inadequate appreciation of the PCB layout and the circuit parasitics that result from the length/width dimensions of the traces, the capacitance between various circuit elements and traces, or the inductance of circuit vias, for example.
As the trend continues to make MOSFET products smaller and more portable, PCB space becomes scarce and relatively more expensive. In addition, system data busses and interface components are typically able to demand a higher priority than power supply space. The power supply and other such power conversion sections are relegated into spare sections of the board.
Accordingly, there is a need for an improved power conversion circuit layout and power MOSFET design that minimizes circuit parasitics in the layout thereby consuming less power, occupying less board space, and operating at high switching frequencies with a fast transient response.